Printing-telegraph-exchange system



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L@ 9 D. ra. PERRY PRINTING TELEGRAPH EXCHANGE SYSTEM Filed oct'. 5J., 1925 fm/enfon- Dafm/d d 10e/Cy WMC 'Patented Sept. 6, 1927.y

UNITED STATES PATENT OFFICE.

DONALD PERRY, OF YONKERS, NEW `YORK, ASSIGNOR T0 AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

PRINTINGiTELEGRArH-EXCHANGE SYSTEM.

Application led October V31., 1925. Serial No. `66,058.

This invention rela-tes to 'printing' tele-l graph exchange systems, an more especlal- 4-ly to systems vwherein communicatlon clrcui'ts are established by means of a'utomatlc 5 switches..I i The object ofthe invention is 'to provide a highly efficient' l communicating s stem wherein a plurality of connections may e eX- tended toward a busy line and the conneclo tions vcompleted to said line in a definite order when'said line becomes idle.

A feature of the invention relates to the means, in a printing telegraph exchange sysy tenfnfor allowing `a calling subscriber to lo maintain an established connection regardless of the busy condition` of the line toward which the established connection is extended.

A further feature relates to a special prefcrenc'e circuit in a printing telegraph system whereby a plurality of subscribers awalting the establishment of va connection with a desired line, whichis busy, may communicate lwith said' line in a particular orderwithout disrupting any of the established connections.

means, in a. printing telegraph exchange system, for delaying the starting of the driving motors at the calling and called stationsv gotconnector switches for establishing con-,-

ncctions to called line. This 'figure also represents schematically a second connector switch and a second subscrlbersstation.

Detailed description.

Figs. 1 and 2 ofthe drawing when ar- .ranged with Fig. .2 at the right of Fig. 1, show suiiicient details of a printing telegraph exchange system embodying the present invention to enable a clear understanding to be attained thereof. `For this purpose it will only.- VAThe calling subscriberV .operates key Anothercfeature resides in the automatic 'has no normal position. Its wipers thereafter, and the stepping circuit for magnet 109 be'Y assumedI that the subscriber at-station;4 101'desires to senda printed telegraph message to the subscriber at station 201 which,

it will be noted, is equipped. for receiving 102 to close its left contacts, whereupon a circuit. is completed from .negative battery, through resistance 107, winding of relay 106, upper inner back contacts of relay 105, over the l'ring side of the calling line, right-hand normal contacts of key 102, back contacts of relay 111, through the busy lamp 104, lefthand contacts of key 102, to ground through vthe upper contacts of the dial 103. Relay 106 operates, andlamp 10e-` is lighted by means of this circuit. Relay 106 connects ground through its right contacts, the winding of relay 108, to the sleeve conductor of the calll ing line asmultipled before the connector switches thus renderingthis line busy thereat. Relay 106 also completes the circuit of the stepping magnet 109 traceable from battery through the winding and interrupter cont-acts of the stepping magnet, left contacts of relay 106, lower back contacts of relay 105, test wiper 155 of the' rotary line switch 150, and the terminal coperating therewith to the sleeve conductor '152 of trunk 151. It is to be noted that switch 150 fore, remain on the contacts associated with the trunk last taken for use.

Should trunk 151 be busy, conductor 152 is grounded, in the manner described hereinis maintained closed, thus causing the brushes of' switch `150 to be 4intermittently advanced until an idle trunk is reached. Should 'trunk y 151 be idle when relay 106 operates, conductor 152 is ungrounded and the stepping magnet109 remains normal. Each time -the'ste ping magnet 109 releases to advance t e brushes, a circuit is' completed from batterv,

through the winding and contacts of'said magnet, winding of cut-oit relay- 105,"to

ground atthe right contacts ofl relay 106'.

So long as brushes of switch .150 are contacting with a. busy trunk, the cut-off relay is shunted by means of the ground connected to the test wiper of said switch, this ground 105 being extended to the lower back contacts of relay 105, left contacts oi relay 106.l

lVhen, however, an idle trunk such as 151 is seized, conductor 152 being ungrounded,

there exists no shunt for relay 105A and this 110 ent of the line relay .106. vThis same ground relay operates in series with the winding of ing slow characteristics ydoes not release until a substitute holding circuit is provided` for relay 105 as described hereinafter.

'The calling line is now extended by means of the, upperfront contacts of relay 105 to the trunk 151'. A circuit may now be traced Ifor the connector line relay 202 traceable from battery, through resistance 206, winding ofl relay 202, next to the upper outer back contacts of relay 205, ring conductor of trunk 151, brush 153 and cooperating terminal of switch 150, upper inner front contacts of relay 105, ring conductor' of the calling line, right contacts of key 102, hack contacts of relay 111, through the busy lamp 104, left contacts of key 102 to ground through contactsof dial 103. Relay 202 operates in this last traced circuit and coinpletes an lobvious operating path for relay 203 to the upper innermost back contacts of relay 205. Relay 203 by means of its left outer contacts connects ound to the sleeve conductor 152 to provi e a locking circuit for the cut-otf-relay 105 which is independis extended through locking contacts of relay 1'05 and the winding of relay -108 to the sleeve multiple of the calling line as it ap#A ears in the connector switches, thusv renders ing this line busy thereat. The connection through switch 150 is controlled by the ,re' v .ing of the line circuit, relay 202 releases and lease relay 203 which in turn is controlled by the key 102 at the calling station. It will be noted that because of the resistance 206 which is included in series with the busy lamp Y104 as described above, `the current in this circuit is reduced and lamp 104 ceases to glow. This serves as an indication to the subscriber that a connector lhas been seized and the circuits are in readiness for selective impulses from the dial 103.

The subscriber now manipulates the dial to send a series of two, impulses corresponding to the tens digit of the desired station 201; As a result of the iii-st opening oit' the circuit by the dial contacts, relay 202 releases but relay 203 being of a slow character retains its armatures attracted during the comparatively brief interval between successive impulses of the series. Accordingly acircu1t is completed from battery through the winding of vertical operating magnet 208, winding of series relay 207 uppermost contacts of the off-normal switch 209, to the left inner front contacts of relay 203back contacts of relay 202, to ground at the innermost back contacts of relay 205.

Magnet 208 and relay 207 operate in this circuit. The Afirst operation of magnet 208 advances the wipers 211, 212, and 213 into cooperative relation with the first bank of terminals in the connector switch 250. Upon the reclosure of theline circuit after the 'transmission of the iirst impulse, relay 202 reoperates and opens the above traced leases,` but relay 207 is slow to release and retains its armatures attracted. Relay 207 therefore transfers the stepping circuit for magnet 208 through the front contacts of relay 207, make-beforebrcak contacts of olfnormal switch 209,l front contacts of relay '203, to the back contact of relay 202. Switch 209 .is operated immediately that 'wipers '211, v212 and 213. are advanced from noryly long period to enable this relay to retract its armatures and vertical magnet 208 releases. With relay 207 released, the stepping circuit is transferred to the rotary magnet 214.

The subscriber next manipulates the dial 103 to transmit -a series ot eight impulses corresponding to the units designation ot station 201. In response to the first opena circuit is closed from battery, through the winding of rotary magnet 214, lower back contacts of relay 205 (thence in parallel) also in parallel from battery through the winding of slow release relay 215, right back contacts of relay 204, back contacts ot relay 207, ott-normal contacts of switch 209, front contacts of relay 203, back contacts ot circuit for vert-ical magnet 208 which rello relayl202 to ground at the contacts of relay 205. Magnet 214,therefore rotates wipers 211, 212 and 213130 the first set of contacts in the second level. the succeeding'seven impulses of the units In a similar manner series cause magnet 214 to be intermittently energized and the wipers.211, 212 and 213 to be advanced into cooperative relation with the eighth set of contacts in thesecond level. It is to be noted that while the wipers of switch 250 are passing over calledline terminals that lthere exists no. complete circuit through the brushes 211 and 212 since relay 205 is deenergized at this time. However, the private wiper 213 may in being advanced pass over intermediate terminals which are vbusy and therefore grounded. Consequently, a circuit may therefore be completed will there 'ore be intermittently energized when brush 213 passes over these busyterm'inals but a substitute operatingI circuit for the rotary magnet 214' is completed through the left front contacts'of rela 215, this circuit being independent of tie right back contacts of relay 204. Consequently ,'since'.

relay 215 is slow to release` it is :maintained energized during the units series of impulses '4 and the circuit for stepping magnet 214 is unbrokenwhen relay 204loperates upon the passage of brush 213 over intermediate busy test terminals. Upon the cessation ofthe transmission of the units'series of impulses, the line. circuitis'maintained closed ,and relay 202 is. continuously energized.` Relay 202 therefore opens Lthe locking circuit of rotaryrelay 2 15 but this relay'bein'g`slow` to .release provides sufficient time for latest to lbe made of the called line. When rotary i magnet 2114 releases after Athe transmission of the last impulse of the units series, wiper 213 is brought into cooperative relation with the test'cond'uctor 251 of vthe called line. If the called line is busy, ground exists on conductor 251. While relay 215 is maintaining its armatures attracted, after thefg transmission Tof the last units 'impulse, 'thegrounded conductor 251 is extended by means of wiper f 213 through-the right front contacts of relay 215 and the lower back contacts of relay 205 to battery .through the winding of relay 204. When therefore relay v215 releases, relay 204 is locked by means vof a circuit traceable from battery through winding of said relay, lowermost contacts of relay 205, normal contacts of relay 215, left middle front contacts of 4relay 204, back contacts of relay 216 to ground at the outer right contacts of 1'elay 203;- vWith relav'z204 operated, the resistance 206 is shunted and the circuit hereinbefore tracedcomprisi'ng the Winding of relay 202 cient current This -serves as an indicationto the calling subscriber-that the called line is busy.

The calling subscriber -because of the urgency of the connection may desire to main-4 tain the switches in their operative condition until the called line becomes idle. Accordingly the connector circuits are so equipped that the cut-through relay 205 is automatically operated to complete the prepared connection with the called line as soon as said line becomes idle. It will be noted that when relay 204 operated in response to the testing of the busy line, the circuit is completed from battery, through the contacts of stepping magnet 217, winding of relay 218, tov ground at the left inner contacts of relay I 204. lRelay 218 operates in this circuit and completes an energizing path 'forrelay 219. Relay219 when o erated in turn causes the energization of t e stepping,V magnet 217. Brush 220 which is associated 'with the magnet 217 is not advanced, however, until mag-. ne't- 217 is deenergized.l It will be noted release type. Thus they provide a definite time interval between the energization and that relays 218y and 219 are ofthe slow-torelease of magnet 217. rUnder control of the 4abovle traced stepping circ'dit, brush 220 isV intermittently advanced over thev succeeding terminals of, the preference switch 260. This stepping operation continues so long as relay 204 remains energized. ,-It to be noted that the-locking circuit for relay. 204 comprises the back contacts or relay 216 and that relay -216 cannot be energized until .brush l220 contacts with the terminal of is therefore completed which maybe traced t from battery, through the winding of relay 222, conductor '251, brush 213, right back contacts of relay 215, upper winding of relay f 205, left outer frontcont-acts of relay 204, winding of relay 216, to ground through terminal 221 and brush 220. 'Relay 216 operates over this circuit and breaks vthe locking circuit of busy test relay 204 which thereupon releases. Relay 204 in turn releases relay 2,16. With rela 204 released, ground is extended through tlie right outer contacts of relay 203, right contacts of relay 216, left middle back contacts of relay 204, upper- Winding'of relay 205, and thence to battery through the winding of cut-oil1 relay 222 as hereinabove'described. Relay 204 in releasing may prevent further operation of the switch 260 by means of the opening lof the left inner contacts of said relay.

The circuit above traced comprising the winding of relay7 222 causes the operation of said relay as well as relav 205. Relay 205 whrn operated immediately. closesa locking circuit for itself by means of its lower winding and lower inner contacts lto ground at the right inner contacts of'relay 203.Y Relay 205 at its upper'inner'front contacts extends ground bymeans of wiper 213 to the conductor 251. thus rendering the called line busy and providing a holdingcircuit for the cut-ofi relay 222, .this circuit being now independent oi relay 204. It will be noted that the polarized mot-or relay A223 at the called station isprovided with two -windings, namely, winding 224 and winding 225. In a similar manner the polarized relay 112 at the calling station is provided with windings 113 and 114. lVith the cut-olif relay 222 of the called station and (cut-off) relay` 205 ol the calling station deenergized, positive battery is connected to the w1ndings 224 and 113 by means ot' back contacts of th-c respective cut-olli i'elays. The polaiity of the current through these windings is such as to maintain the armatures of the relays 223 and 112 against their respective back contacts, lVhen therefore, relay 222 operates in series with relay 205 as above described, thepositive battery through 'the uppermost outer back contacts of relay 205 is replaced by negative battery over a circuit traceable from negative battery, through the upper winding of differential relay 239, uppermost front'lcontacts of relay 205 over the tip of trunk 151, brush 154, and cooperating terminal ot' switch 150, upper outer front contacts of relay 105, tip conductor of the calling line. winding 113 of relay 112, through the printer 11G to ground through the normal contacts ol' relay 111.

Under control of this last traced circuit, the armature of relay 112 is attracted to itsl liront contact thereupon closing a holding circuit for the polarized relay 112 which is completed from the source of. power 117, resistance 118, winding of relays 111 and 121, holding winding 114, resistance 119, front contacts of relay 112, returning through resistance 123 to the power source. Relays 111 and l121 operate in this circuit.

.Relay 121, by-means of its .front contacts,

' connects the powers source 117 with the printer driving motor 124. Relay 111 in operating, brings about the reversal of current through the windings 224 of the polarized relay at the called station. This circuit may be traced from negative battery, through the upper winding. of differential relay 239, uppermost front contacts of relay 205, tip conductor of trunk 151 and thence through thc winding 113 of relay 112 as hereinabove described through printer 116, front contacts of relay 111, right contacts of key 102, returning over the ring side of the calling line, upper inner front contacts of relay 105, brush 153, ring conductor of trunk 151, next to the uppermost -front contacts of relay 205, lower winding of differential relay 239, brush 211, and cooperating terminal in switch 250, uppermost front contact of relay 222, winding 224 of relay 223 to ground through resistance 228.

This reversalof' current through the windf ing 224 causes the armature of relay 223 to close its front contact, thereby completing a circuit from the power source 229 Oto'opcrate relays 230 and 231 as Wellfas to provide a holding circuit for relay "223. Re-

lays 230 land v231 Icorrespond to relays 111 conductor of trunk 151, brush 154, outer front contacts of relay 105, tip conductor ot' the calling line, winding 113 of relay 112 through the printer 116, front Contact of relay 111, right contacts of key 102, ring side of the calling line, upper inner front contacts of relay 105, brush 153, ring conductor of trunk151, next to the uppermost i front contacts of relay205, lower winding of differential relay 239, brush 211, conductor 253, uppermost front contact of relay 222, winding 224 of relay 223, through the printer 227, iront contacts of relay 231, innermost front contacts of relay 222, conductor 254, brush 212, next to the upper inner contacts of relay 205 to positive battery. The starting of the motor at the calling station as above described, serves as van indication to the subscribed thercat that the connection is completed and that printer signals may now be transmitted. It is to be noted that the maintenance of the established connection is under control of the diff'erential relay 239, which at its contacts, provides a holding circuit for the release control relay 203. Consequently, either subscriber may break without disestablishing the connection.

Disconneczz'on.

When the communication is completed, the subscriber at station 101 operates key 102 to the i'ight and holds it in this position until the motor 124 is stopped. tion of key 101 in this manner extends ground through the right rcontacts thereof,

The operay ergized when key 102 is operated, consequently the contacts of relay 239 are broken and release control relayv203 -`'is deenergized-` After a short interval, relay203 retracts its armatures, thus opening the locking circuit for the through relay 205 and the cut-oi relay 105 Which thereuponrelease. A circuit may nowbe traced from groundthrough the upperrinnermost. back contacts of relay 205, back contacts of relay 202, left back contacts of relay 203, contacts of the off-normal switch 209, to battery through the winding lof release magnet 233. Under the control of this circuit magnet` 233 restores the wipbroken and these relays release.

ers 211, 212 and 213 to the normal position. Restoration of the connector to normal also causes the release of cut-olf relay 222. The `release of relay 222 connects positive battery to the Winding 224 of relay 223, thus causing the armatuie of this relay tobe attracted to its back contact. The holding circuit-for relays 230 and 231 is thereupon Relay 230 in releasing,jdisconnects the motor 222 from the power source 229. In a similar manner, the -releasef/of relay 205, by means of its upper most/back contacts reverses the current through the winding 113 of relayj112, causing the armaturel of this relay to open its front contacts and release 'relays 111 and 121. 'Ihe release of relay 121 disconnects the motor 124 from the source of power 117. The stopping of motor` 124 serves as a signal to thecalling subscriber that key 102 may be restored. The circuits and connector switch are thus completely returned to normal.

sumed that when the wipers 211 and 2124 were positioned on thecalled line terminals,

o that'this line was busy. Should, however, to conductor 251, as above described, said this line be idle when relay 204 is connected conductor is ungrounded and relay 204 remains normal. rIfhe'refore, an interval after the termination of dialing, the slow relay 215 releases and disconnects the test relay 204 from. the test wiper 213. Since relay 204 remains normal, relay 216 cannot operate regardless of whether or not theswitch 260 is being operated under control of some other connector as hereinafter described. Accordingly, immediately that relay 215 releases, the circuit hereinbefore traced for relays 205 and-222 is completed.v These .relays complete the connection of the' calling and Vthe called lines and prepare the printing circuits, as already described. It is seen, therefore, that relay 216 and the preference circuits included within the dotted rectangle ydo not function when the called line is idle.

calling Zines arwm'tmg hac.

In the detailed description given hereinbefore, it was assumed that line 100 alone was calling the busy station 201. It was lthe same called seen that under this condition, the established connection through switches 150 and- 250 is maintained until lthe wanted station becomes idle. It will now be'aSSume that both lines and 300 are awaiting connection with the station'201 and that this station is busy. In this case, busy test relayv ed'as well. as busy test relay 3 04 associated with connector 450. Relay 204, therefore, closes the circuit for relay 218 which in turn operates relay 219, whereupon stepping magnet 217 operates as already described.

After an interval determined by the release w of relays'218 and 219, the steppingmagnet.

218 releases and advances brush 220 to the terminal associated with the next connector. As pointed out liereinbefore, this stepping process continues so long as the busy ytest relay associated with any connector served by switch 260 is operated. IVhen, therefore,

in switch 450, test wiper 413 cooperatingtherewith, upper winding of relay 305," left outer front' contacts of relay 304, windin of'relay 316, terminal 235 to the grounded brush 220. Relays 316, 305 and 222 operate in this circuit. Relay 316 in operating, opens ythe locking circuitof test relay 304 which thereupon releases. It is to lbe noted that connector 450 has associated therewith relays similar to those shown associated with connector 250. A few of thesev relays only are shown. Thus, relay 316 corresponds to relay 216; relay 304 corresponds to relay 204, etc. As described in connection with relay 205, the operation ofrelay 305 grounds the conductor 251 to render the station 201 busy. Since relay 204 s still locked under control of relay 216, brush 220 continues to advance.Y When terminal 221 is reached, since conductor 251 has been meanwhile grounded by wiper 413, relay 216 fails to operate (since it is shun-ted), consequently, brush 220 continues to rotate until station 201 becomes idle. At the instant brush-220 reaches terminal 221 after station 201 becomes idle, relay 216 operates and brings labout the operation of relay 205 in the manner deemed to be already familiar.

' ence 'switch 220 common to all the connectors,

each connector having an individual terminal such as 235, in this switch. It will be understood, however, that the invention may equally well be applied to telegraph systems' accommodating more than 100 subscribers in which case first selective switches may be 'inserted between the line switches and the connectors. In this case, a preference switch having a multiple of levels similar to that shown cooperating with brush 220 is supplied, each-level being adapted to serve a. particular hundred subscribers lines. Furthermore, the station 201 has been shown as a receiving station only, but from a consideration of the description taken in conjunction with the showing of the station 101, it is believed that it will be perfectly obvious as to the manner in which the station 201 could be adapted for both sending and receiving printed telegraph messages..

'What is claimed is:

`l.' In a signaling system, a first calling line, a second calling line, a called line, automatic switches for extending connections between said calling lines and said called line, means eiiective while said called line is busy for maintaining said extended connections/open, and means edective when said called line becomes idle for determinin the order in which said connectioris shal be completed.

2. In a printing telegraph exchange-system, a first calling line, a second calling line, a called line, automatic switches Voperated under control of the calling lines for extending printing telegraph communication circuits from said calling lines to said called lines, means individual to each established connection for maintaining the same open while the called .line is busy, and' a preterence switchfor determining the order in which. said last mentioned means shall operate to complete said open connections.

3. In a printing telegraph exchange system, a plurality of calling lines, a called line, al plurality of connector switches, means controlled by each of said calling lines for operating a different connector switch to prepare a printing telegraph circuit between said calling lines and said called line, means responsive to an idle condition of the called line for completing one of said prepared circuitswithout releasing the other prepared circuits and for rendering said called line busy, and means effective. when said called line becomes idle for completing said other prepared circuits in a definite order.

4. In a signaling system, a plurality of calling lines, a called line, a plurality of connector switches having traveling wipers, means controlled by said calling lines for bringin the wipers of a corresponding plu,

' rality o connector switches into cooperative relation with the called line terminals, and a preference switch for determining the order in which said connectors are effective to establish telegraph communication'v circuits to said called line.

5. In a printing telegraph exchange system, a plurality of calling lines, called'lines, a plurality of selectively operable connector switches, means under control of said call-l ing lines for operating a corresponding number of connector switches to seize the terminals of one of sald called lines, continuity controlling means individual to each connector for closmg the prlntino communication circuit extending through the brushes of the f associated.- connector switch,4 and' means common to said connector switches connector switches for determining the order in which said prepared-channels shall be completed. v

7 In a printing telegraph exchange system, calling lines, a called line, a plurality of connecter switches Afor preparing simultaneously channels of communication between said calling lines and said called line, and means comprising a relay individual to each connector and a rotary switch common to'said connectors for determining the order in which said channels of communication shall be completed.

8. In a printing telegraph exchange system, the combination of a called line, a plurality ot connector switches in which said called line terminates, means for operating said plurality .of switches to seize said called line terminals to prepare telegraph communication circuits thereto, meansV responsive to a busy condition of said called line for causing said connectors to await the removal of the busy condition, and a preference switch for determining the order of completion of said prepared circuits by said connectors.

9. In a printing telegraph system, a calling station, a called station, printing appapower source at each station with its associated driving means at the time said stations are interconnected.l

10. In a communication system, the combination of a plurality of separate stations f with .power driving means at each station,

automatic means for establishing a communication circuit between any two of said stations, and means responsive to the establishment of such a circuit for starting in operation the driving means at each of the interconnected stations.

11. lIn a printing telegraph system, the combination of a plurality of stations, a telegraph printer and a motor therefor at each station, said mot-ors being normally 4at rest, automatic means for establishing a communication circuit between any two of said stations, and means eifective immediately on the establishment of such-faicircuit .for starting in operation the motors at the interconnected stations.

12.- In a printing telegraph exchange syspower circuit, and means responsive 4to thel interconnection of said stations for causlngf tive power circuits.

tem., a calling station, a called station, anteomatic switches for establishing a printing power circuit for each motor, a relay at e'ach stationfor controlling the associated said relays to operate to close theirrespec- 13. In a printing telegraph exchange systern, a calling station, a called station, a central oiice, automatic switches at the 'central oiice, a 'motor at each stationl for driving the printing apparatus thereat, a normally opened power circuit for each motor, means under control of they calling station' for operating'a train of said switches toesta'blish a communication circuit with the called sta,- tion, a polarized relay at each station for controlling the .power circuit thereat, and

means responsive to the establishment #of said communication circuit for reversing the curi-ent therein to cause the polarized relays at both the calling and called stations to operate to close the respectivevpower cir-v cuits.

In testimony whereof, I have signed my A i name to-this specification this 30th daybf October, 1925.

. 'DONALD B. PERRY. 

